A system for processing an optical fiber includes: a draw furnace, the draw furnace containing an optical fiber preform; a bare optical fiber drawn from the optical fiber preform, the bare optical fiber extending from the draw furnace along a process pathway; and a slow cooling device operatively coupled to and downstream from the draw furnace, the slow cooling device exposing the bare optical fiber to a slow cooling device process temperature in the range form 1000° C. to 1400° C., wherein the bare optical fiber passes through the slow cooling device at least two times.

A system for processing an optical fiber includes: a draw furnace, said draw furnace containing an optical fiber preform; a bare optical fiber drawn from said optical fiber preform, said bare optical fiber extending from said draw furnace along a process pathway; and a slow cooling device operatively coupled to and downstream from said draw furnace, said slow cooling device exposing said bare optical fiber to a slow cooling device process temperature in the range from 1000° C. to 1400° C., wherein the bare optical fiber passes through the slow cooling device at least two times.

An optical fiber has a central axis. The optical fiber includes a core made of silica glass and extending along the central axis, a cladding made of silica glass and surrounding the core, the cladding extending along the central axis, and a coating layer made of resin and surrounding the cladding, the coating layer extending along the central axis. An outer diameter of the cladding varies along the central axis. A residual stress in a direction along the central axis varies along the central axis, the residual stress being averaged over the core and the cladding in a cross section perpendicular to the central axis. A deviation from an average value of the outer diameter and a deviation from an average value of the residual stress have signs opposite to each other.

A system for positioning an optical preform in a furnace is provided that includes an upper muffle and a downfeed handle assembly with a tube defining a first end and a second end, the second end extending into the upper muffle. A handle is disposed within the tube. A second end of the handle extends into the upper muffle and a seal assembly is positioned around both the tube and the handle. The first end of the handle extends through the seal assembly and a drive assembly is coupled with the downfeed handle.

An optical fiber draw system and method of operating thereof. The method includes positioning a downfeed handle for supporting an optical fiber preform within a furnace such that the downfeed handle is movable within the furnace. The method further includes operating one or more heating elements to thermally heat at least a portion of an upper muffle extension disposed within the furnace, the one or more heating elements being moveable with the downfeed handle.

An optical fiber draw system and method of operating thereof. The method includes positioning a downfeed handle for supporting an optical fiber preform within a furnace such that the downfeed handle is movable within the furnace. The method further includes operating one or more heating elements to thermally heat at least a portion of an upper muffle extension disposed within the furnace, the one or more heating elements being moveable with the downfeed handle.

A method for drawing an optical fibre from an optical fibre preform with a core section, a cladding section, a first gap and a second gap. The optical fibre preform is attached to an optical fibre draw tower through a handle. In addition, the optical fibre preform is connected to a vacuum system to supply and remove gas from the first gap and the second gap. Moreover, the gas is supplied to create a thermal barrier between the core section and the cladding section during heating of the optical fibre preform. Further, the optical fibre preform is heated inside a heating furnace to draw the optical fibre from the optical fibre preform.

A drawing furnace for drawing a glass element includes: a furnace body having an upper end and a lower end. The furnace body includes a top annular plate, an A/C induction coil capable of accepting electrical current and producing an oscillating electronic signal, a cylindrical susceptor capable of producing heat output, a cylindrical quartz beaker, an insulating material disposed between the susceptor and the beaker, and a bottom annular plate housing and supporting at least one of the susceptor, the beaker, and the insulating material. wherein the furnace body comprises a central longitudinal axis; A rotational drive system operably connected to the bottom annular plate by an annular rotation gear system rotates the bottom annular plate along with the susceptor, beaker, and/or insulating material at a frequency between 0.01 to 10 Hz. The electrical current and oscillation frequency determine the heat output of the susceptor.

The application provides a method for automatically processing a conical tip of an optical fiber preform, including: step 10: suspending an optical fiber preform requiring conical tip processing on a suspension component, where the optical fiber preform moves downward vertically along with the suspension component; step 20: arranging a furnace body below the suspension component, where a preset depth is set inside the furnace body, and after the optical fiber preform moves to the preset depth inside the furnace body, the furnace body is heated; step 30: arranging an automatic cutting component below the furnace body, where a preset temperature is set inside the furnace body, after a temperature inside the furnace body reaches the preset temperature, a bottom of the furnace body is opened to make the optical fiber preform melt to form a conical tip, and the automatic cutting component cuts the molten conical tip.

A gas branching apparatus that branches and supplies a gas to first to N-th supply targets, includes first to N-th pipes wherein the first to N-th pipes are each branched into first to N-th branch pipes on a downstream end side, and wherein the i-th branch pipes of the respective first to N-th pipes are connected in common to the i-th supply target, and the i-th branch pipes of the respective first to N-th pipes are provided with valves, respectively, where i denotes each of integers of 1 to N.